Convert into simpler and more efficient code.
Convert into simpler and more efficient code.

- Use `str.format` instead of string concatination.
- Remove meaningless invocation of `_type.rjust(...)`,
    - `len(description) - longest_desc_length` is always less than or equal to 0.
    - It means `_type.rjust(longest_desc_length - len(description))`?

landaire/deoplete-swift